i2c: i2c-sh_mobile support for new ICIC bits

Add support for a new version of the IIC block
found in the SH-Mobile ARM line of processors.

Prototype patch written by Nishimoto-san.
Tested on sh7377 and sh7372.

Signed-off-by: NISHIMOTO Hiroki <nishimoto.hiroki@renesas.com>
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c
index d2fabd9..598c49a 100644 (file)
--- a/drivers/i2c/busses/i2c-sh_mobile.c
+++ b/drivers/i2c/busses/i2c-sh_mobile.c
@@ -119,8 +119,10 @@ struct sh_mobile_i2c_data {
        struct i2c_adapter adap;
 
        struct clk *clk;
+       u_int8_t icic;
        u_int8_t iccl;
        u_int8_t icch;
+       u_int8_t flags;
 
        spinlock_t lock;
        wait_queue_head_t wait;
@@ -129,6 +131,8 @@ struct sh_mobile_i2c_data {
        int sr;
 };
 
+#define IIC_FLAG_HAS_ICIC67    (1 << 0)
+
 #define NORMAL_SPEED           100000 /* FAST_SPEED 400000 */
 
 /* Register offsets */
@@ -155,6 +159,8 @@ struct sh_mobile_i2c_data {
 #define ICSR_WAIT              0x02
 #define ICSR_DTE               0x01
 
+#define ICIC_ICCLB8            0x80
+#define ICIC_ICCHB8            0x40
 #define ICIC_ALE               0x08
 #define ICIC_TACKE             0x04
 #define ICIC_WAITE             0x02
@@ -162,6 +168,9 @@ struct sh_mobile_i2c_data {
 
 static void iic_wr(struct sh_mobile_i2c_data *pd, int offs, unsigned char data)
 {
+       if (offs == ICIC)
+               data |= pd->icic;
+
        iowrite8(data, pd->reg + offs);
 }
 
@@ -203,6 +212,14 @@ static void activate_ch(struct sh_mobile_i2c_data *pd)
        else
                pd->iccl = (u_int8_t)(num/denom);
 
+       /* one more bit of ICCL in ICIC */
+       if (pd->flags & IIC_FLAG_HAS_ICIC67) {
+               if ((num/denom) > 0xff)
+                       pd->icic |= ICIC_ICCLB8;
+               else
+                       pd->icic &= ~ICIC_ICCLB8;
+       }
+
        /* Calculate the value for icch. From the data sheet:
           icch = (p clock / transfer rate) * (H / (L + H)) */
        num = i2c_clk * 4;
@@ -212,6 +229,14 @@ static void activate_ch(struct sh_mobile_i2c_data *pd)
        else
                pd->icch = (u_int8_t)(num/denom);
 
+       /* one more bit of ICCH in ICIC */
+       if (pd->flags & IIC_FLAG_HAS_ICIC67) {
+               if ((num/denom) > 0xff)
+                       pd->icic |= ICIC_ICCHB8;
+               else
+                       pd->icic &= ~ICIC_ICCHB8;
+       }
+
        /* Enable channel and configure rx ack */
        iic_set_clr(pd, ICCR, ICCR_ICE, 0);
 
@@ -592,6 +617,12 @@ static int sh_mobile_i2c_probe(struct platform_device *dev)
                goto err_irq;
        }
 
+       /* The IIC blocks on SH-Mobile ARM processors
+        * come with two new bits in ICIC.
+        */
+       if (size > 0x17)
+               pd->flags |= IIC_FLAG_HAS_ICIC67;
+
        /* Enable Runtime PM for this device.
         *
         * Also tell the Runtime PM core to ignore children